1. Technical Field
The present invention relates to capacitors and methods for manufacturing the same.
2. Related Art
When capacitors to be used for ink jet recording heads, ferroelectric memories and the like are fabricated, dielectric materials such as PZT and electrode materials such as Pt are used. Because the aforementioned materials are difficult to be etched, fine processing may be very difficult. For example, when etching is conducted with resist masks, side surfaces of dielectric layers and electrodes may have a gentler slope, as their etching selection ratio is small, and steep etching cannot be achieved.
In this connection, for example, Japanese laid-open patent application JP-A-11-354510 describes a technology to etch electrode material such as Pt wherein hard masks composed of TiN or the like other than resist masks are used as masks, and oxygen is added to etching gas. On the other hand, because PZT composing a dielectric layer is an oxide material, etching that is conducted with etching gas and oxygen added thereto may lower the etching rate, cause a micro-loading phenomenon and the like. For example, an etching selection ratio of PZT to a TiN mask may become about 1.